Equisetaceae

Reed-like herbs along margins or rivers or swamps, with creeping underground stems, aerial stems erect, sometimes with branching at the nodes, sometimes with a whorl of smaller branches, longitudinally grooved, articulate, with a sheath at each node, the internodes green and rough to the touch, hollow, leaves reduced to a single whorl of minute, +/- deciduous teeth on the rim of the sheath at each node. Sporangia borne on the backs of stalked, peltate sporangiophores, arranged in a compact terminal cone; spores rounded, green, with 4 coiled bands.

Distribution

Basically a northern hemisphere family of a single genus with c. 24 species. Equisetum debile is the sole species in Papuasia.